Automatic trailer braking system



May 23, 1950 H. D. COOK AUTOMATIC TRAILER BRAKING SYSTEM 1 Filed July 51, 1946 A INVENTOR. ffl'erfier/fl [50% ATI'D R N EYS Patented May 23, 1950 UNITED STATES AUTOMATIC TRAILER, BRAKING SYSTEM Herbert D. Cook, Worthington, Ind.

Application July 31, 1946, Serial No. 687,279

1 Claim.

My present invention relates to an improved automatic trailer braking system and more particularly to the automatic means for applying the trailer brakes as the towing vehicle slows down, and further to the means incorporated in the embodiment of my invention whereby the trailer is permitted to be backed even though the brake applying means is in operation.

In the accompanying drawings I have i1lustrated one complete example of the physical embodiment of my invention according to the best mode I have thus far devised but it will be understood that various alterations and changes may be made in the exemplified structure within the scope of the appended claim.

In the drawings Figure 1 is a bottom plan View of the brake mechanism of my invention as applied to a trailer.

Figure 2 is a transverse vertical sectional view taken at line 2-2 of Figure 1.

Referring now to the drawings, I have illustrated a draw bar 2 attached to the towing vehicle not shown. A plate 4 is bolted to the draw bar and this plate is fashioned with side flanges 6 and a tongue portion 8 and an opening therethrough as 10.

A slide member 12 is positioned to reciprocate on the plate in confinement between the flanges and this slide is formed with. a ball l4 for coaction with the link l6 having a curved end l8 and an adjustment section 20 with screw 22 for securing the link to the ball. The connecting link 24 is attached to the frame 26 of the trailer 28. Thus as the trailer is pulled the link and slide member will assume a rearward position on the plate whereas when the towing vehicle slows, the slide will move forward.

The brake rod 3!! is formed with a hooked end 32 engaging the hole H! in the plate 8, and the rear end of the rod is enlarged and internally threaded as at 34 to receive the bolt 36. This bolt is pivotally attached to the lever 38 which is journaled in the fluid shock absorber of conventional design as 48, mounted as at 42 on the trailer 28. An actuator 44 is pivoted at it to the lever 38 and is connected to the floating lever 48 at the pivot 49. This floating lever is fashioned with a pin 52! engaging the guide frame 52 and the spring 54 releasably retains the pin in the position shown in Figure 2 subject to movement therein upon the application of excess pressure of an amount more than sufficient to operate the brakes.

OFFICE The piston rod 56 is attached to the lower end of the lever 43 and operates within the cylinder 58 to apply the fluid therein through the pressure line 60 and the branches 62 to the wheels 64 mounted on axle 66 and springs 68 to apply the brakes.

From the above description of the construction and operation, it will be apparent that the device of my invention will effect the automatic application of the brakes of the trailer wheels almost instantaneously with the application of the brakes of the towins. vehicle. The longitudinal movement of the slide l2 does not exceed one to one and one-half inches and the intermediate shock absorbed in the mechanical linkage will prevent the application of the trailer brakes which might otherwise result from jolts or jars, or uneven roadways. A definite movement of the trailer toward the towing vehicle is required to actuate the brake mechanism.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

A brake applying mechanism for a towing vehicle and a towed vehicle comprising a draw bar, adapted to be connected to a towin vehicle, a plate secured to said draw bar, side flanges on said plate and an 'apertured tongue portion on said plate extending outwardly of said draw bar at the rear end thereof, a slide member mounted on said plate between said flanges, a ball connection on said slide member centrally thereof. a connecting link secured to the frame of the towed vehicle, a connecting member having a curved forward end adapted to coact with said ball connection, a coupling means mounted for adjustment on said connecting member and coacting with said ball to secure the connecting member to said ball, a brake rod positioned in parallel relation to said connecting link and having a hooked front end adapted to coact with said apertured tongue portion and said rod is provided with an enlarged internally threaded rear end, a bolt threadably mounted in said enlarged end, a shock absorber mounted on the towed vehicle, a lever for said shock absorber and the bolt carried by the rod is pivotally connected to said lever, an actuator pivoted to said lever above the pivoted connection to said boltv a floating lever mounted on the towed vehicle and said actuator is adapted to be pivotally connected to said lever adjacent the upper end thereof, a guide frame on the towed vehicle, a pin in the upper end of the floating lever slidably mounted in said guide frame, a spring connected REFERENCES CITED 7 t said floating level between the end carrying The following references are of record in the the pin and the connection of the actuator thereme of this patent; to to retain said pin in the forward end of the guide frame, a piston rod connected to the lower 5 UNITED STALES PATENTS end of the actuator and said piston is mounted Number Name Date within a fluid cylinder connected to the brakes 1,652,254 Schlagenhauf D 13, 1927 on the towed vehicle, whereby when the towing 1,966,670 Klammer July 17, 1934 vehicle is in motion the brakes will be free but 2,051 522 Graham 13, 193 p n dec ra on 9f sa ow n ve v a d :0 2,116,952: Turpin c May 3, 1938 slide mefiaber wills-bemused to slide to move said 56,590 er May 2, 1939 rod to apply the brakes of the towed vehicle. 2,139,335 Ace t, 1, Feb, 6, 1940 2,215,586 Hunter Sept. 24, 1940 D QQQK- 2,354 261; M Namar uly 25, 1944 

